title: Penicillin facilitates the entry of antisense constructs into Streptococcus mutans.
abstract: Antisense oligonucleotides (AS-ODN) target genes in a sequence-specific manner inhibit gene function and have potential use as antimicrobial agents. Cell barriers, such as peptidoglycan, cell surface proteins and lipopolysaccharide membranes, prevent delivery of AS-ODN into the bacterial cell, limiting their use as an effective treatment option. The β-lactam antibiotic penicillin was examined for its ability to deliver phosphorothioate oligodeoxyribonucleotides (PS-ODNs) and γ(32) P-ODN into Streptococcus mutans OMZ175. Treatment of lag-phase S. mutans OMZ175 cells with penicillin and FBA (PS-ODN targeting the fructose-biphosphate aldolase gene), resulted in prolonged suppression of growth (> 24 h) and fba expression (656.9 ± 194.4-fold decrease at 5 h). Suppression of both cell growth and fba expression corresponded with a greater amount of γ(32) P-ODN becoming cell associated, with a maximum γ(32) P-ODN concentration per cell achieved 5 h after penicillin treatment (6.50 ± 1.39 × 10(8) molecules per CFU). This study confirms that for S. mutans OMZ175, the peptidoglycan layer acts as a major barrier preventing AS-ODN penetration and suggests that the use of agents such as penicillin that interfere with peptidoglycan integrity can significantly increase the uptake of PS-ODN by these cells.
authors.affiliation: Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
authors.forename: Felicity S A
authors.initials: FS
authors.lastname: McLeod
authors.forename: Robin S
authors.initials: RS
authors.lastname: Simmonds
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D002455:Cell Division / Q000187:drug effects; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005821:Genetic Techniques; D020319:Oligodeoxyribonucleotides, Antisense / Q000235:genetics / Q000378:metabolism*; D010406:Penicillins / Q000494:pharmacology*; D010457:Peptidoglycan / Q000378:metabolism; D013295:Streptococcus mutans / Q000187:drug effects* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D020319:Oligodeoxyribonucleotides, Antisense; D010406:Penicillins; D010457:Peptidoglycan
keywords: antimicrobial; lytic; mutans; phosphorothioate; zoocin A